dpot-backend/Application/Features/Api/Auth/VerifyEmail/Handler.cs

using Application.Abstractions.Data;
using Application.Abstractions.Messaging;
using Domain.Entities.EmailVerification.ValueObject;
using SharedKernel.Results;
using Microsoft.EntityFrameworkCore;

namespace Application.Features.Api.Auth.VerifyEmail;

internal sealed class Handler(
    IAppDbContext db
) : ICommandHandler<Command, Result<VerificationType>>
{
    public async Task<Result<VerificationType>> Handle(Command request, CancellationToken ct)
    {
        // 이메일 유효성 검사
        if (string.IsNullOrWhiteSpace(request.Email))
        {
            return Result.Failure<VerificationType>(Error.Problem("Auth.EmailRequired", "이메일은 필수입니다."));
        }

        if (string.IsNullOrWhiteSpace(request.Code))
        {
            return Result.Failure<VerificationType>(Error.Problem("Auth.CodeRequired", "인증번호는 필수입니다."));
        }

        var email = request.Email.Trim().ToLower();

        // 인증번호 조회 (미인증, 만료되지 않은 것)
        var verifyNumber = await db.EmailVerifyNumber.Where(e => e.Email == email && e.Type == request.Type && !e.IsVerified && e.Expiration > DateTime.UtcNow).OrderByDescending(e => e.CreatedAt).FirstOrDefaultAsync(ct);
        if (verifyNumber is null)
        {
            return Result.Failure<VerificationType>(Error.NotFound("Auth.CodeNotFound", "인증번호가 올바르지 않거나 만료되었습니다."));
        }

        // 코드 일치 확인
        if (verifyNumber.Code != request.Code.Trim())
        {
            return Result.Failure<VerificationType>(Error.Problem("Auth.CodeMismatch", "인증번호가 일치하지 않습니다."));
        }

        // 인증 완료 처리
        verifyNumber.MarkVerified();

        // 회원가입 인증인 경우 이메일 인증 완료 처리
        if (request.Type == VerificationType.Registration)
        {
            var member = await db.Member.FirstOrDefaultAsync(m => m.Email == email, ct);
            if (member is not null && !member.IsEmailVerified)
            {
                member.MarkEmailVerified();
            }
        }

        await db.SaveChangesAsync(ct);

        return Result.Success(request.Type);
    }
}